IRAS galaxies in the Perseus cluster

We cross-correlate the optical catalogue of galaxies in the field of the Perseus cluster (Abell 426) with IRAS PSC sources. The optical catalogue comprises data on 660 galaxies brighter than B25 ≈ 19.5 (Brunzendorf & Meusinger 1999). A sample of 19 IRAS galaxies is found. According to their redshifts, 17 galaxies are likely members of the Perseus cluster, two are background galaxies. The sample-averaged FIR excess is higher than expected for normal galaxies. The optical morphology of the IRAS galaxies is evaluated on CCD images taken in the B band at a seeing of about 1′′, complemented by CCD images taken in the redshifted Hα band or in theR band. Individual descriptions are presented along with the B band images for all of the IRAS galaxies. A substantial fraction of the galaxies in the IRAS sample exhibit signs for morphological distortion. A correlation between the FIR activity and the strength of distortion is indicated. On the other hand, there are approximately as many disturbed/interacting galaxies in the Perseus cluster region without IRAS counterparts as IRAS galaxies. The IRAS galaxies are much less concentrated towards the cluster centre than typical bright cluster galaxies. For the distorted non-IRAS galaxies, such a trend is less pronounced. These differences may be related to rapid stripping of gas as galaxies enter the cluster.